Autism is a gut-wrenching diagnosis for many families. Though children who suffer from autism spectrum disorder (ASD) have widely varying ranges of functionality, many of those who are diagnosed have difficulty communicating, poor social skills, delayed development, and repetitive behaviors.

To the dismay of parents and practitioners, the Centers for Disease Control and Prevention reported last year that the number of children with autism in the US had risen between 2000 and 2012 from one in 150 to one in 68. It’s no wonder that parents, medical professionals, and autism advocates are desperate to find something that can manage — or, better yet, cure — the disease.

Now researchers from the University of California, San Diego School of Medicine have published a research article in the Annals of Clinical and Translational Neurology that shows a tentative link between a 100-year old medication and improvements in children with autism.

Led by Dr. Robert Naviaux, the research hinges on the idea that there is one underlying cause of autism in children despite the disorder’s varying symptoms. Though scientists have previously discovered genes and environmental triggers that may increase the risk of autism, no definitive cause has been found that can explain all ASD.

But Naviaux believes that there is a fundamental metabolic problem in all people with ASD — namely, that cells in affected people experience abnormal levels of something that Naviaux has termed the “cell danger response” (CDR).

The CDR, Naviaux explained to Seeker, happens when a cell responds to external stressors or toxins. He describes this process as the cell hardening its membranes, ceasing interaction with neighbors, and withdrawing into itself until the danger has passed.

Naviaux believes that the CDR process gets stuck in children with autism, and that it can permanently alter how the cells interact with their external environment. When this happens in early child development, Naviaux believes it results in the development of autism and various other chronic childhood disorders.

The trial aimed to “un-stick” the CDR cycle using an infusion of an old drug called suramin, which was first developed in 1916 to treat parasitic diseases, including African sleeping sickness (trypanisomiasis) and river blindness (onchocerciasis).

Suramin is also the only drug used in humans that can “inhibit extracellular ATP signaling,” Naviaux said, giving cells that are stuck in the CDR cycle the “all-clear signal” that they need to continue with their normal development.

“After the single dose, it was almost like a roadblock had been released.”

Naviaux and his team first tried suramin in mice models with autism-like features in 2013, and found that normal mouse social behaviors were restored. The UC San Diego trial was initially meant to be a phase one trial that only tested the safety of suramin in children, noted John Rodakis, the founder and president of N of One: Autism Research Foundation, which supported the trial.

But, Rodakis told Seeker, the results were “mind-blowing.”

The study had a very small sample size; only ten children (all of whom were boys) were involved in the double-blind, placebo-controlled trial. They were matched together based on factors including severity of symptoms, IQ, and age. Then, one child in each pair was given an intravenous infusion of suramin, for a total of five children that took the medication.

“After the single dose, it was almost like a roadblock had been released” in the treated children, Naviaux remarked. All five of the boys who received the drug began to show improvements in symptoms, including displaying increased communication and social activity.

The parents of these five children were also thrilled, according to a batch of anonymous statements from them that the lab released to accompany a press release.

“Suramin produced the most dramatic improvement in autism symptoms that we have ever seen with anything we have tried,” one parent wrote.

“Nothing has come close to all the changes in language and social interaction and new interests that we saw after suramin,” said another.

Yet even proponents of the study are quick to note that there are limitations to the trial, with the most obvious being the small sample size of the children studied.

“We would have loved to have done a much larger trial,” said Rodakis. “We just didn’t have the funding for it.”

Both Rodakis and Naviaux noted that they did not receive any federal funding for the trial, and had to rely on donations and grassroots support from autism parents and advocates.

All of the children who received the medicine exhibited a rash, the authors noted, which may have compromised the double-blind nature of the research. They also pointed out that the children who showed benefits from suramin only improved temporarily. Naviaux said that the most improvement was reported three weeks after the infusion — children began to regress to previous levels of functionality after that point.

Finally, while the study designers tried to control the placebo effect as much as possible, autism research has a notoriously difficult time parsing genuine benefits from false positives. It’s not uncommon for small studies to claim that they have identified a potential cure for autism, but then have these hopes dashed after more rigorous study. One such case was the hormone secretin, which in the late 1990s was briefly thought to produce an improvement in ASD symptoms. Upon more testing, the science didn’t hold up.

"It's a really interesting study — very small, but well done," said Dr. Sanford Newmark, a pediatrician who specializes in treating autism. He noted that the trial's findings are "premature," however. Newmark, who is the medical director of the Osher Center for Integrative Medicine at the University of California, expects that his patients are going to start asking about suramin, but he doesn't think that they should experiment with it yet until more is learned about its possible effects.

Regardless of the ultimate validity of these new preliminary results, Naviaux and Rodakis believe that this research has shown enough promise to warrant follow-up trials that will test suramin on more children at various doses.

“If the future studies show that there’s continued health benefits,” Naviaux said, “this could be a game-changer for families with autism.”